Dissolve 20 grams of copper acetate monohydrate in 200 ml of hot water. If you don’t have a scale, don’t despair. Dissolve the copper acetate in warm water to create a saturated solution. You’ll know you have enough of the powder added when it stops dissolving in the liquid.

If you see a scum of undissolved material, stir in a couple of drops of acetic acid (vinegar).

Place the container in an undisturbed location to allow crystal to grow.

Blue-green crystals should start to appear within a couple of days. You can allow them to grow on their own or can you can select one perfect crystal to use as a seed crystal to grow larger crystals.

If you wish to grow a large single crystal, place the seed crystal in a new container and add the copper acetate solution from the old container.

When you are pleased with the crystal, remove it and place it on a paper towel to dry.